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author | Frank Rowand <frank.rowand@sony.com> | 2018-10-04 20:24:17 -0700 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-02-06 17:30:15 +0100 |
commit | 5006496fb2c8ded3a1211dcf9ee53070205ebe7f (patch) | |
tree | 0bf4cb05702eefa087f02d11838eff0779239615 /drivers/of | |
parent | 3edc2fac969abcc8754f8364fc32c5ba4b2c881b (diff) | |
download | linux-stable-5006496fb2c8ded3a1211dcf9ee53070205ebe7f.tar.gz linux-stable-5006496fb2c8ded3a1211dcf9ee53070205ebe7f.tar.bz2 linux-stable-5006496fb2c8ded3a1211dcf9ee53070205ebe7f.zip |
of: overlay: add tests to validate kfrees from overlay removal
commit 144552c786925314c1e7cb8f91a71dae1aca8798 upstream.
Add checks:
- attempted kfree due to refcount reaching zero before overlay
is removed
- properties linked to an overlay node when the node is removed
- node refcount > one during node removal in a changeset destroy,
if the node was created by the changeset
After applying this patch, several validation warnings will be
reported from the devicetree unittest during boot due to
pre-existing devicetree bugs. The warnings will be similar to:
OF: ERROR: of_node_release(), unexpected properties in /testcase-data/overlay-node/test-bus/test-unittest11
OF: ERROR: memory leak, expected refcount 1 instead of 2, of_node_get()/of_node_put() unbalanced - destroy cset entry: attach overlay node /testcase-data-2/substation@100/
hvac-medium-2
Tested-by: Alan Tull <atull@kernel.org>
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/of')
-rw-r--r-- | drivers/of/dynamic.c | 29 | ||||
-rw-r--r-- | drivers/of/overlay.c | 1 |
2 files changed, 30 insertions, 0 deletions
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c index ecea92f68c87..0ea0b8f2e25b 100644 --- a/drivers/of/dynamic.c +++ b/drivers/of/dynamic.c @@ -333,6 +333,25 @@ void of_node_release(struct kobject *kobj) if (!of_node_check_flag(node, OF_DYNAMIC)) return; + if (of_node_check_flag(node, OF_OVERLAY)) { + + if (!of_node_check_flag(node, OF_OVERLAY_FREE_CSET)) { + /* premature refcount of zero, do not free memory */ + pr_err("ERROR: memory leak before free overlay changeset, %pOF\n", + node); + return; + } + + /* + * If node->properties non-empty then properties were added + * to this node either by different overlay that has not + * yet been removed, or by a non-overlay mechanism. + */ + if (node->properties) + pr_err("ERROR: %s(), unexpected properties in %pOF\n", + __func__, node); + } + property_list_free(node->properties); property_list_free(node->deadprops); @@ -437,6 +456,16 @@ struct device_node *__of_node_dup(const struct device_node *np, static void __of_changeset_entry_destroy(struct of_changeset_entry *ce) { + if (ce->action == OF_RECONFIG_ATTACH_NODE && + of_node_check_flag(ce->np, OF_OVERLAY)) { + if (kref_read(&ce->np->kobj.kref) > 1) { + pr_err("ERROR: memory leak, expected refcount 1 instead of %d, of_node_get()/of_node_put() unbalanced - destroy cset entry: attach overlay node %pOF\n", + kref_read(&ce->np->kobj.kref), ce->np); + } else { + of_node_set_flag(ce->np, OF_OVERLAY_FREE_CSET); + } + } + of_node_put(ce->np); list_del(&ce->node); kfree(ce); diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c index 1e058196f23f..7613f7d680c7 100644 --- a/drivers/of/overlay.c +++ b/drivers/of/overlay.c @@ -373,6 +373,7 @@ static int add_changeset_node(struct overlay_changeset *ovcs, return -ENOMEM; tchild->parent = target_node; + of_node_set_flag(tchild, OF_OVERLAY); ret = of_changeset_attach_node(&ovcs->cset, tchild); if (ret) |